From b4fe8dfa2131a0eae4fd37a3128369462145c204 Mon Sep 17 00:00:00 2001 From: Tony Garnock-Jones Date: Sun, 11 Mar 2012 08:17:49 -0400 Subject: [PATCH] Comment on freshen* --- presence/unify.rkt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/presence/unify.rkt b/presence/unify.rkt index a0e2abc..ce7578e 100644 --- a/presence/unify.rkt +++ b/presence/unify.rkt @@ -164,6 +164,10 @@ (and s (apply-subst s a-env))) ;; Utility used by freshen and canonicalize below. +;; Must visit the term in the order specified by canonicalize +;; below. Here we rely both upon Racket's left-to-right evaluation +;; order and upon defined struct-mappers traversing their arguments in +;; some deterministic order. (define (freshen* t var-handler canon-handler) (define env (make-hash)) ;; cheeky use of mutation (let walk ((t t))